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From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	kvm@vger.kernel.org
Cc: Joey Gouly <joey.gouly@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oupton@kernel.org>,
	Zenghui Yu <yuzenghui@huawei.com>, Fuad Tabba <tabba@google.com>,
	Will Deacon <will@kernel.org>,
	Quentin Perret <qperret@google.com>
Subject: [PATCH v2 13/30] KVM: arm64: Clean up control flow in kvm_s2_fault_map()
Date: Fri, 27 Mar 2026 11:36:01 +0000	[thread overview]
Message-ID: <20260327113618.4051534-14-maz@kernel.org> (raw)
In-Reply-To: <20260327113618.4051534-1-maz@kernel.org>

From: Fuad Tabba <tabba@google.com>

Clean up the KVM MMU lock retry loop by pre-assigning the error code.
Add clear braces to the THP adjustment integration for readability, and
safely unnest the transparent hugepage logic branches.

Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/mmu.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index ee2a548999b1b..c6cd6ce5254be 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1897,10 +1897,9 @@ static int kvm_s2_fault_map(struct kvm_s2_fault *fault, void *memcache)
 
 	kvm_fault_lock(kvm);
 	pgt = fault->vcpu->arch.hw_mmu->pgt;
-	if (mmu_invalidate_retry(kvm, fault->mmu_seq)) {
-		ret = -EAGAIN;
+	ret = -EAGAIN;
+	if (mmu_invalidate_retry(kvm, fault->mmu_seq))
 		goto out_unlock;
-	}
 
 	/*
 	 * If we are not forced to use page mapping, check if we are
@@ -1908,16 +1907,17 @@ static int kvm_s2_fault_map(struct kvm_s2_fault *fault, void *memcache)
 	 */
 	if (fault->vma_pagesize == PAGE_SIZE &&
 	    !(fault->force_pte || fault->s2_force_noncacheable)) {
-		if (fault->fault_is_perm && fault->fault_granule > PAGE_SIZE)
+		if (fault->fault_is_perm && fault->fault_granule > PAGE_SIZE) {
 			fault->vma_pagesize = fault->fault_granule;
-		else
+		} else {
 			fault->vma_pagesize = transparent_hugepage_adjust(kvm, fault->memslot,
 									  fault->hva, &fault->pfn,
 									  &fault->fault_ipa);
 
-		if (fault->vma_pagesize < 0) {
-			ret = fault->vma_pagesize;
-			goto out_unlock;
+			if (fault->vma_pagesize < 0) {
+				ret = fault->vma_pagesize;
+				goto out_unlock;
+			}
 		}
 	}
 
@@ -1951,7 +1951,9 @@ static int kvm_s2_fault_map(struct kvm_s2_fault *fault, void *memcache)
 	if (fault->writable && !ret)
 		mark_page_dirty_in_slot(kvm, fault->memslot, fault->gfn);
 
-	return ret != -EAGAIN ? ret : 0;
+	if (ret != -EAGAIN)
+		return ret;
+	return 0;
 }
 
 static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
-- 
2.47.3



  parent reply	other threads:[~2026-03-27 11:36 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-27 11:35 [PATCH v2 00/30] KVM: arm64: Combined user_mem_abort() rework Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 01/30] KVM: arm64: Extract VMA size resolution in user_mem_abort() Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 02/30] KVM: arm64: Introduce struct kvm_s2_fault to user_mem_abort() Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 03/30] KVM: arm64: Extract PFN resolution in user_mem_abort() Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 04/30] KVM: arm64: Isolate mmap_read_lock inside new kvm_s2_fault_get_vma_info() helper Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 05/30] KVM: arm64: Extract stage-2 permission logic in user_mem_abort() Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 06/30] KVM: arm64: Extract page table mapping " Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 07/30] KVM: arm64: Simplify nested VMA shift calculation Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 08/30] KVM: arm64: Remove redundant state variables from struct kvm_s2_fault Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 09/30] KVM: arm64: Simplify return logic in user_mem_abort() Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 10/30] KVM: arm64: Initialize struct kvm_s2_fault completely at declaration Marc Zyngier
2026-03-27 11:35 ` [PATCH v2 11/30] KVM: arm64: Optimize early exit checks in kvm_s2_fault_pin_pfn() Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 12/30] KVM: arm64: Hoist MTE validation check out of MMU lock path Marc Zyngier
2026-03-27 11:36 ` Marc Zyngier [this message]
2026-03-27 11:36 ` [PATCH v2 14/30] KVM: arm64: Kill fault->ipa Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 15/30] KVM: arm64: Make fault_ipa immutable Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 16/30] KVM: arm64: Move fault context to const structure Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 17/30] KVM: arm64: Replace fault_is_perm with a helper Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 18/30] KVM: arm64: Constrain fault_granule to kvm_s2_fault_map() Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 19/30] KVM: arm64: Kill write_fault from kvm_s2_fault Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 20/30] KVM: arm64: Kill exec_fault " Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 21/30] KVM: arm64: Kill topup_memcache " Marc Zyngier
2026-03-27 14:49   ` Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 22/30] KVM: arm64: Move VMA-related information to kvm_s2_fault_vma_info Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 23/30] KVM: arm64: Kill logging_active from kvm_s2_fault Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 24/30] KVM: arm64: Restrict the scope of the 'writable' attribute Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 25/30] KVM: arm64: Move kvm_s2_fault.{pfn,page} to kvm_s2_vma_info Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 26/30] KVM: arm64: Replace force_pte with a max_map_size attribute Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 27/30] KVM: arm64: Move device mapping management into kvm_s2_fault_pin_pfn() Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 28/30] KVM: arm64: Directly expose mapping prot and kill kvm_s2_fault Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 29/30] KVM: arm64: Simplify integration of adjust_nested_*_perms() Marc Zyngier
2026-03-27 11:36 ` [PATCH v2 30/30] KVM: arm64: Convert gmem_abort() to struct kvm_s2_fault_desc Marc Zyngier

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